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Australia conducts world-first research on fragile X

ELEANOR HALL: Australian scientists are conducting the world's first research into the full spectrum of a mutant gene which is thought to be a leading cause of intellectual disability and autism.

The research will look at carriers of the mutated gene, known as fragile X.

Sufferers of fragile X syndrome have welcomed the research, saying it will help with treatment and identification of all people who suffer from it.

In Melbourne, Rachel Carbonell reports.

RACHEL CARBONELL: Professor Kim Cornish from Monash University's school of psychology and psychiatry is one of Australia's leading researchers of fragile X - a genetic mutation of the X chromosome which can cause a range of physical and intellectual disabilities.

KIM CORNISH: All of us carry a particular gene in our X chromosome, we carry many genes in all of our chromosomes and this particular gene is called the fragile X mental retardation 1 gene, which we all have.

In some individuals, in some families the gene is slightly expanded and it is during this expanded range that you become a carrier of fragile X. You may not know that you're a carrier of fragile X, but when you then pass it onto your child, in some cases that gene expands and becomes a large expansion and with that we then have a child with fragile X syndrome.

And it's when that gene becomes a large expansion and the gene is then switched off do we have all the symptoms of fragile X syndrome, including intellectual delay, including autism features, including all the behavioural and academic problems.

RACHEL CARBONELL: Professor Cornish is part of a team conducting world first research on the whole spectrum of fragile X, not just those who show clinical symptoms.

KIM CORNISH: The research currently happening in Australia between Sydney and Melbourne is unique because it's a nationwide study of carriers of fragile X, of which you'll know there are nearly 70,000 or more carriers of fragile X in Australia.

So what's unique about it is that it is the first Australian study to look at both men and women in adulthood and in later adulthood with fragile X syndrome as carriers.

So it's a unique study that will provide a wealth of new information about how carriers with fragile X perform everyday life, what are the clinical problems, when do they emerge and how best can we treat them?

RACHEL CARBONELL: People who have fully fledged fragile X syndrome often have disabilities, and many are diagnosed with autism.

Professor Cornish says the Australian research is reaching much further by investigating the carriers of fragile X, who may have few or no symptoms but will pass the syndrome onto their children.

KIM CORNISH: In male carriers with fragile X we know from a decade of research now that are proportion of men who carry the medium expansion of the fragile X gene, who are carriers, will go on to present with a neurological disorder called fragile X ataxia tremor syndrome, which is a devastating disorder typically as a clinical onset in the mid to late 60s - has tremor, has severe cognitive dysfunction decline.

What we are trying to achieve is to see what are the early symptoms of those, of that disorder in the 30s and the 40s.

RACHEL CARBONELL: And what about in women?

KIM CORNISH: In women the neurological condition does not, is not prevalent so the biggest clinical issue for women with the carrier, who are carriers of fragile X, is that they are at a greater risk of having early menopause, at greater risk of having ovarian failure in their late 20s, in their early 30s.

So again, understanding beginning our study in the early 20s will allow us to see what symptoms are there early and which are not present in women who don't go on to develop ovarian failure.

RACHEL CARBONELL: There isn't any cure for fragile X for carriers or those who have the syndrome, but there are specific treatments and management for fragile X syndrome, and the earlier it's identified the better.

Christine Kelleher is a board member of the Fragile X Association of Australia and a carrier of fragile X. She has a son and a daughter with fragile X syndrome.

CHRISTINE KELLEHER: I have two out of my three children have fragile X. This wasn't diagnosed until my younger son was 11. He's now 23. It just became apparent. He was assessed as being globally and developmentally delayed and we always felt that there must be a reason for this but the professionals told us that basically it was just on the autistic spectrum.

And it wasn't until a colleague of mine who herself has two boys with fragile X that she urged me to have them tested and so we tested my son and he was a full mutation, fully affected fragile X.

And so then the rest of the family were tested and it transpired that I was the carrier and I had absolutely no idea, and my daughter was also fully affected fragile X, which then answered a whole load of questions as I reared them during their earlier childhood.

RACHEL CARBONELL: Christine Kelleher says sufferers like her family are very happy that such research is being carried out in Australia.